To a large extent the notion that mass shootings are trending is based on the often-cited reporting by Mother Jones, an award-winning online news organization. Mother Jones assembled a data tally of “random” mass shootings over the past couple of decades derived from news reports and collective memories of events, and concluded that mass shootings are indeed on the increase.
Not only is Mother Jones’s decision to disqualify cases based on certain criteria hard to defend, the criteria themselves were not necessarily applied consistently. Mother Jones included the 1993 Chuck E. Cheese robbery/massacre of four people committed by a former employee, but excluded the Brown’s Chicken robbery/massacre of seven victims that occurred the very same year, presumably because two perpetrators were involved in the latter incident or perhaps because these gunmen had no prior connection to the restaurant.
Source: Boston Globe. Read full article. (link)